AAC .50 Suppressor photo
The below photo comes from an article about the AAC Cyclops suppressor that Andy posted on the official AAC blog. The photo illustrates the size really well.

Looks similar in size to a massive custom 12 gauge suppressor I saw on a Remington 870 recently.
I think a slight modification might knock off a few more decibels…
Tom, haha
( http://www.mygunculture.com/2008/12/50-caliber-suppressor-new-and-improved.html )
Wow thats all im going to say